A squirrel cage induction motor requires _______ maintenance as compared to a slip ring induction motor.

The correct answer is option 1.

A squirrel cage induction motor requires significantly low maintenance as compared to a slip-ring induction motor.

3ϕ Induction motor 

• A 3ϕ induction motor is an electromechanical energy conversion device that converts 3-phase input electrical power into output mechanical power. 
• This motor runs with a speed slightly less than the synchronous speed.
• The speed of a 3ϕ induction motor is:

\(N_r=N_s(1-s)\)

where, N_r = Rotor speed

N_s = Synchronous speed

s = Slip

Types of 3ϕ induction motor

1.) Squirrel cage induction motor

• It consists of a cylinder of steel laminations, with aluminum or copper conductors embedded in its surface.
• The rotor bars are slightly skewed which increases the length of the copper bars thereby increasing the resistance of the rotor bars, hence the starting performance of the induction motor will be improved.
• These motors do not have slip rings and brush assembly, hence less maintenance is required.
• Due to the absence of slip rings and brush assembly, speed control is not possible and the starting current is very high.

​2.) Wound induction motor

• These motors consist of slip rings and brush assembly, that is connected to the external resistor.
• At starting, the external resistance is maximum which limits the starting current.
• As speed increases, the external resistance is short-circuited through tapping provided, thus providing the speed control of the motor.